The W3C Vehicle Information API is a proposal that aims to enables connectivity through in-vehicle infotainment systems and vehicle data access protocols. This API can also be leveraged by web applications running on mobile devices that access the data resources of a connected passenger vehicle.

This specification does not dictate or describe the access protocol or transport method used for the data connection. Data may come from numerous sources including OBD-II, CAN, LIN, etc. Bluetooth, WiFi, or cloud connections are all possible.

The purpose of this specification is to promote an API that enables application development in a consistent manner across participating automotive manufacturers. It is recognized, however, that the mechanisms required for access or control of vehicle Properties may differ between automobile manufacturers, makes and models. Furthermore, different automobile manufacturers can expose different Properties that can be read or set by an application.

As a result of these constraints, this specification shall allow for automobile manufacturer-specific extensions or restrictions. Extensions are only permitted for interfaces that are not already described by this API, and must be implemented to conform within the format and guidelines existing in this specification. If a Property is restricted, the automobile manufacturer would omit the optional feature in their implementation (see the Availability Section).

The target platform supported by the specification is exclusively passenger vehicles. Use of this specification for non-passenger applications (transportation, heavy machinery, marine, airline infotainment, military, etc.) is not prohibited, but is not covered in the design or content of the API and therefore may be insufficient.

Initially, a typical use case of Vehicle Information might be the implementation of a 'Virtual Mechanic' application that provides vehicle status information such as tire pressure, engine oil level, washer fluid level, battery status, etc. Future use case innovations in transportation, safety, navigation, smart energy grid and consumer infotainment and customization are all possible through this specification.

Web developers building interoperable applications based upon this API, will help empower a common web platform across consumer devices and passenger vehicles consistent with the Web of Things.

Introduction

The Vehicle Information API provides operations to get access to the vehicle data
(henceforth "properties") available from vehicle systems and also to change (write) a number of
properties. Vehicle data types are available in the Vehicle Data specification.

This specification defines conformance criteria that apply to a single
product: the user agent that implements the interfaces that it
contains.

Implementations that use ECMAScript to implement the APIs defined in this
specification MUST implement them in a manner consistent with the ECMAScript
Bindings defined in the Web IDL specification [[!WEBIDL]], as this
specification uses that specification and terminology.

Terminology

The
Promise provide a convenient way to get access to the result of an operation.

Security and privacy considerations

It is expected that security of vehicle APIs described in this document is based on permissions dictated by:

The JavaScript runtime under which the APIs are used – in some cases

The underlying operating system – always

No separate permission or access control model will be defined for vehicle APIs. Depending on a specific platform, the user agent used may have to provide tools to generate permissions for application descriptors as required by the OS. Android is an example under which such a descriptor (Android app manifest) has to be generated if the runtime maps its apps to OS-level apps.

The VehicleInterface
interface represents the base interface to get all vehicle properties.

Promise get(optional Zone zone)

MUST return the Promise. The "resolve" callback in the promise is used to pass the vehicle data type that corresponds to the specific VehicleInterface instance.
For example, "vehicle.vehicleSpeed" corresponds to the "VehicleSpeed" data type. VehicleInterfaceError is passed to the 'reject' callback in the promise.

The VehicleSignalInterface
interface represents vehicle signals that, as a rule, and unlike vehicle configurations, can change values, either programmatically
(necessitating support for set method) or due to external events and occurrences, as reflected by subscription management.

Promise set(object value, optional Zone zone)

MUST return Promise. The "resolve" callback indicates the set was successful. No data is passed to resolve. If there was an error,
"reject" will be called with a VehicleInterfaceError object

History

The History API provides a way for applications to access logged data from the vehicle. What data is available and how much is up to the implementation. This section is OPTIONAL.

readonly attribute any value

MUST return value. This is ANY Vehicle Data Type.

readonly attribute DOMTimeStamp timestamp

MUST return time in which 'value' was read by the system.

readonly attribute History? history

MUST return History interface if the platform supports the History API

Promise get(Date begin, Date end, optional Zone zone)

MUST return Promise. The "resolve" callback in the promise is used to pass an array of HistoryItems.

readonly attribute boolean isLogged

MUST return true if this attribute is logged

readonly attribute Date? from

MUST return Date in which logging started from. Returns null if isLogged is false.

readonly attribute Date? to

MUST return Date in which logging of this attribute ends. Returns null if isLogged is false.

/// check if there is data being logged for vehicleSpeed:
if(vehicle.vehicleSpeed.history.isLogged)
{
/// get all vehicleSpeed since it was first logged:
vehicle.vehicleSpeed.history.get(vehicle.vehicleSpeed.history.from, vehicle.vehicleSpeed.history.to).then( function ( data ) {
console.log(data.length);
});
}

Use-Cases

The primary purpose of this specification is to provide web developers the ability to access and set vehicle
information through a simple common set of operations including get, set, subscribe, and unsubscribe. Thus
normative use cases pertain to this access and do not cover higher application of business level use cases.